Improvement in packing projectiles for rifled ordnance



J. W. COC N.

Projec' No. 56,712. Patented July 31, 1866.

UNITED STATES PATENT OFFICE.

JOHN WEBSTER GOCHRAN, OF NE'WYORK, N. Y.

IMPROVEMENT lN PACKING PROJECTILES FOR RIFLED ORDNANCE.

Specification forming part of Letters Patent No. 56,712, dated July 31, 1866.

To all whom it may concern:

Be it known that I, JOHN WEBSTER Goon- RAN, of the city, county, and State of New York, have invented certain new and useful Improvements in Elongated Projectiles for Ordnance; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the annexed drawings, making a part of this specification, in which Figure 1 is a side view of the projectile. Fig. 2 is a central longitudinal section of the same. Fig. 3 is a rear-end view, representing the base of the same.

Similar letters of reference indicate similar parts in all the figures.

This invention consists in a novel construction of the base of the projectile, and of the metal packing attached thereto, and a novel mode of applying lubricating material in relation therewith, whereby the rotation of the ball in its passage along the rifle-grooves of the gun is effectually insured with a lighter packing than has -been commonly employed, and the effective lubrication of the bore and grooves of the gun is provided for.

To enable those skilled in the art to understand the construction and operation of my invention, I will proceed to describe it with reference to the drawings.

At a short distance from the base of the projectile A there is, in its exterior, a circumferential V-shaped groove, m, and from this groove to the base there are a series of longitudinal grooves, a a, so arranged as to leave the intervening fins (1 and e alternately thicker and thinner. Around the faces of the fins d d andc ethere is snugly fitted the band I), of copper or other comparatively soft but tough metal, the front portion of which is contracted in conical form to fit the rear part of the circumferential groove, as shown at t z in Fig. 2. This band leaves the grooves a a open at the base only. The groove m is fitted, outside of the portion t of the band, with cotton, hemp, or other fibrous material saturated with tallow or other suitable lubricating material, and outside of this is wound one or more layers of copper wire, (1, the outer surface of which is flush with that of the projectile A.

The thicker fins d (l have in their faces shallow longitudinal grooves c 0, into which the band I) is depressed for two reasons-via, first, that it may insure the turning of the projectile with the said band as the latter is caused to rotate by its movement in the groove of a rifled gun; and, second, that it expand to fit the bore and grooves without being burst.

The grooves c 0 and the corresponding depressions in the band are of such depth that the limited expansion necessary to make the band fit the bore and grooves will not so far withdraw the said depressions from the grooves as to prevent the said depressions from obtaining the necessary hold upon one side of each groove to insure the rotation of the projectile.

Such being the construction of the invention, the manner of its operation in the gun is as follows: When the powder is ignited the gases generated thereby enter the grooves aand expand the copper band b into close contact with the bore of the gun, and into the rifle-grooves also, if the gun be rifled, and at the same time acting against that part of the said band which is turned inward over the front of the grooves a a to drive the said band forward, thereby causing the circumferential expansion of the fibrous material f, and its covering of copper wire, and pressing out the wire against the bore and into the rifle grooves. By these means all windage is prevented and the shot is caused to receive a rotary motion from the rifle-grooves, while the lubricating matter be ing expelled from the fibrous material between the coils of wire by the forward pressure on the band lubricates the bore in advance of the passage of the band b.

It will also be seen that those parts of the band I) which are pressed into the shallowgrooves c in the fins d d of the shot will yield somewhat to the force exerted by the explosion of the powder and allow the band 0 to expand, as aforesaid, without danger of tearing or bursting the same, which would be likely to occur if the expansive force of the powder were exerted upon a band formed in a true circle, which could not expand except by the stretching of the metal. The wire (1' not only protects the fibrous material from being torn by the edges of the grooves of a rifled 2. The grooves c 0, arranged with reference gun, but also assists the band I) in producing to the grooves a a and m for the reception of the rotary motion. depressions of the expanding band, as and for What I claim as my invention, and desire the purpose herein set forth.

to secure by Letters Patent, is

l. The band b, saturated fibrous material j, J. W. GOGHRAN. and coiled. Wire cl, in combination with each other and with the circumferential and longi- Witnesses: tudinal grooves in the projectile, substantially HENRY T. BROWN as and for the purpose herein specified. J. W. OoolvlBs. 

